Salt and Calcium Have Been Dropping Over Winter

[mbbeaubi]

I live in South Carolina and the weather here gets cold but not so much that I worry about freezing. The coldest my pool water gets is mid 40s and maybe a couple times a year the pump kicks on at night for freeze protection.

Anyways, I don’t close my pool, I just test it weekly and balance chemicals.

I noticed over the last month that my salt dropped from 3000 to 2000 and my CH dropped from 400 to 300. My pool water level was low and I had to add water.

Suspecting a leak I did the bucket test. That showed no leaks.

Is there any other explanation for what I am observing besides a leak?

 

[HermanTX]

Welcome to TFP
Excessive rain will dilute your pool water. Evaporation does not.
Have you had a lot of rain where your pool filled up? Do you have an overflow drain? Do you have an autofill line?
These items can mask a water exchange which affects the pool chemistry. Rain fills up pool to overflow then autofill kicks in when water level drops, all which cause dilution.

 

[JoyfulNoise]

Redo the bucket test with the pumps off for 24 hours and then do it with the pumps running as normal.

If those numbers are accurate, then pool water is being exchanged with fresh water. It's either overflow from excess rain, an autofill/wall drain combo that's pushing water out of the pool, or it's a leak. Evaporation would not move numbers like that.

 

[Bperry]

I live in South Carolina and the weather here gets cold but not so much that I worry about freezing. The coldest my pool water gets is mid 40s and maybe a couple times a year the pump kicks on at night for freeze protection.

Anyways, I don’t close my pool, I just test it weekly and balance chemicals.

I noticed over the last month that my salt dropped from 3000 to 2000 and my CH dropped from 400 to 300. My pool water level was low and I had to add water.

Suspecting a leak I did the bucket test. That showed no leaks.

Is there any other explanation for what I am observing besides a leak?

What are you using to test the water?